NASA could offer contracts as a prize to the first three teams to make orbital flight that reaches the ISS. As long as the vehicles are deemed safe enough and can be fitted with a docking hatch. If not a cash prize can be given instead.

Last week I have read in "Die Welt" (german newspaper) that last Friday something quite similar to a competition was ending - for the design etc. of the Crew Exploration Vehicle. Now NASA is working on making its choice for two of these designs. Sounds like public subscription but might have been as a prize too.

Because ot these thoughts I'm asking wether it might be a good idea to set out prizes to compete for by developing privately those spacecrafts NASA of its own were working on in the past: Crew Return Vehicle, Orbital Space Plane, Single Stage to Orbit.

That would meet the Know How and the experiences the XPRIZE-teams gained by development of theier suborbital spacecrafts.

The cash offered should be significantly less than the estimated development and construction cost estimated by NASA and the prototypes should be allowed to be smaller than required for NASA-purposes bcause they will be more testbeds and subject to studies.

Another sort of prizes might set out for development of spacecrafts or modules integratable to NASA missions or NASA spacecrafts. The cash offered should give incentives to reduce costs compared to NASA estimates too in this sort of prizes.